As the population of the Internet users increases, various Web services, which are based on a set of standardized technologies, are now offered through the Internet. However, as the market becomes more competitive, atomic Web services are not sophisticated enough to meet users¡¦ needs, and the concept of Web services-based workflow emerges accordingly. Web services-based workflow is a workflow composed of several related activities, aiming to achieve certain task, and for each activity, there can be a set of candidate Web services to be selected. The goal is to make a selection, which optimizes the QoS of the entire workflow. Although numerous methods are proposed to solve this QoS-based Web services selection problem, most of them are based on a static QoS model, which cannot accurately reflect the real QoS measures, and as a result, methods based on this static model will not necessarily derive the optimal solution even in the average case. Therefore, in this thesis, we adopt a probability-based model, which represents QoS measures as probability mass functions, and propose a branch and bound algorithm for selecting Web services from a set of candidate Web services. Under this QoS model, the goal is to maximize the probability of meeting the QoS goal subject to some QoS constraints. As demonstrated by the results of our experiments, it is much more probable for a workflow to meets the QoS goal by executing the selection derived by the probability-based approach.

The last decade has demonstrated steady growth and utilization of Web Service technology. While Web Services have become significant in a number of IT domains such as eCommerce, digital libraries, data feeds, and geographical information systems, common portals or registries of Web Services require manual publishing for indexing. Manually compiled registries of Web Services have proven useful but often fail to include a considerable amount of Web Services published and available on the Web. We propose a system capable of finding, binding, and integrating Web Services into an index in an automated manner. By using a combination of guided search and web crawling techniques, the system finds a large number of Web Service providers that are further bound and aggregated into a single portal available for public use. Results show that this approach is successful in discovering a considerable number of Web Services in the GIS(Geographical Information Systems) domain, and demonstrate improvements over existing methods of Web Service Discovery.

Made available in DSpace on 2015-03-05T13:56:59Z (GMT). No. of bitstreams: 0 Previous issue date: 16 / Hewlett-Packard Brasil Ltda / Os serviços e as aplicações de computação móvel possuem exigências para o seu bom funcionamento, cujo atendimento é dificultado em virtude do ambiente altamente dinâmico em que estão inseridos. Nesse ambiente, o gerenciamento passa a ser peça chave para propiciar o funcionamento harmonioso tanto da infra-estrutura física, quanto das aplicações. As soluções existentes para essa finalidade se restringem à monitoração dos recursos de hardware, não oferecendo mecanismos para o gerenciamento das aplicações executadas nos dispositivos portáteis. Esta dissertação propõe uma arquitetura para gerenciamento de ambientes de computação móvel que permite obter e disseminar, de forma flexível, informações sobre o funcionamento dos dispositivos e, sobretudo, das aplicações. A arquitetura é baseada no padrão Web Services Distributed Management, que propõe o emprego de serviços Web na modelagem de interfaces de gerenciamento. A dissertação apresenta, ainda,resultados obtidos com a instanciação da arquitetura em um ambiente / Mobile computing services and applications pose special requirements to run properly, whose satisfaction is hampered due to the highly dynamic environment where they are executed. In this environment, management becomes an important element to enable harmonious functioning of both the mobile physical infrastructure and the applications. Current solutions are restricted to resource monitoring, and do not provide mechanisms to manage the applications running on top of the mobile devices. This work proposes an architecture to manage mobile computing environments, which allows one to obtain and disseminate, in a flexible manner, information about the devices and the applications. The architecture is based on the Web Services Distributed Management standard. This work also presents results obtained with the instantiation of the architecture in a real setup

ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / In this paper, we discuss ways in which web services can be used in future T&E scenarios, from the initial hardware setup to making dynamic configuration changes and data requests. We offer a comparison of this approach to other standards such as SNMP, FTP, and RTSP, describing the pros and cons of each as well as how these standards can be used together for certain applications.

<p>Användandet av Web Services har ökat de senaste åren, det är relativt lätt att utveckla dessa tjänster och de kan användas i de allra flesta miljöer. Ett bekymmer är dock säkerhetsfrågan. Denna uppsats studerar de vanligaste teknikerna för att säkra Web Services, beskriver hur de kan användas samtidigt diskuterar fördelar och nackdelar med flera av dem. Till sist ges förslag på hur Web Services i olika typer av miljöer kan säkras.</p> / <p>The usage of Web Services has increased during recent years, its relatively easy to develop and can be used in almost any environment. One concern however is the security aspect. This essay studies the most common techniques for securing Web Services and describes how they can be used. It also discusses some pros and cons about them. Finally this paper suggests some ways to secure Web Services used in different environment.</p>

Researchers have spent years understanding resource utilization to improve scheduling, load balancing, and system management through short-term prediction of resource utilization. Early research focused primarily on single operating systems; later, interest shifted to distributed systems and, finally, into web services. In each case researchers sought to more effectively use available resources. Since schedulers are required to manage the execution of multiple programs every second, short-term prediction has focused on time frames ranging from fractions of a second to several minutes. The recent increase in the number of research studies about web services has occurred because of the explosive growth and reliance on these services by most businesses. As demand has moved from static to dynamic content, the load on machine resources has grown exponentially, periodically resulting in temporary loss of service. To address these short-term denial-of-service issues, researchers have tried short-term prediction to manage scheduling of service requests. What researchers have not considered is that the same methods used for single step short-term prediction can also be used for long-term prediction if a coarse granularity of samples is used. Instead of using one or more samples per second, a coarser aggregate of minutes or hours more accurately emulates the long-term patterns. This research has shown that simple moving averages and exponential moving averages as a prediction technique can be used to more accurately predict hourly, daily, and weekly seasonal patterns of resource utilization for web servers. Additionally, this research provides a foundation where using a resource prediction within a confidence interval range could be more useful to an administrator or system software than a single prediction point. When the focus shifts to a range, a set of probabilities can establish normal function within that system. For distributed systems, it will provide the ability to notify other systems when resource utilization is no longer normal before that system is unable to issue a notice of overloading. For web systems it can be used to provide a warning, permitting the instantiation of a second system to begin load balancing during unscheduled heavy loads. In both cases, the availability of the system can be improved by predicting a resource utilization level and the confidence interval within which that resource use has historically fallen.

In the modern geographic information systems, COTS software has been playing a major role. However, deploying heterogeneous GIS software has the tendency to form fragmented data sets and to cause inconsistency. To accomplish data consolidation, we must achieve interoperability between different GIS tools. In my thesis project, I developed Vector and Raster Data Adapters to implement the spatial data consolidation. I deployed ArcIMS to publish the spatial data and metadata onto Internet. Furthermore, the SOAP-Based GIS Web services are implemented to achieve the enterprise information system integration. The contribution of ours in this project is we have streamlined the COTS GIS server, the J2EE coordinator server, the web service provider components, and the COTS web publishing tools into a hybrid web service architecture, in which the enterprise information system integration, the web publishing, and the business-to business online services are uniformed.

Regression testing is essential to ensure software quality. Regression Test-case selection is another process wherein, the testers would like to ensure that test-cases which are obsolete due to the changes in the system should not be considered for further testing. This is the Regression Test-case Selection problem. Although existing research has addressed many related problems, most of the existing regression test-case selection techniques cater to procedural systems. Being academic, they lack the scalability and detail to cater to multi-tier applications. Such techniques can be employed for procedural systems, usually mathematical applications. Enterprise applications have become complex and distributed leading to component-based architectures. Thus, inter-process communication has become a very important activity of any such system. Messaging is the most widely employed intermodule interaction mechanism. Today's systems, being heavily internet dependent, are Web-Services based which utilize XML for messaging. We propose an RTS technique which is specifically targeted at enterprise applications.

The goal of this research is to provide a supporting Web services architecture, consisting of a service model and catalog, to allow discovery and automatic orchestration of geospatial Web services. First, a methodology for supporting geospatial Web services with existing orchestration tools is presented. Geospatial services are automatically translated into SOAP/WSDL services by a portable service wrapper. Their data layers are exposed as atomic functions while WSDL extensions provide syntactic metadata. Compliant services are modeled using the descriptive logic capabilities of the Ontology Language for the Web (OWL). The resulting geospatial service model has a number of functions. It provides a basic taxonomy of geospatial Web services that is useful for templating service compositions. It also contains the necessary annotations to allow discovery of services. Importantly, the model defines a number of logical relationships between its internal concepts which allow inconsistency detection for the model as a whole and for individual service instances as they are added to the catalog. These logical relationships have the additional benefit of supporting automatic classification of geospatial services individuals when they are added to the service catalog. The geospatial service catalog is backed by the descriptive logic model. It supports queries which are more complex that those available using standard relational data models, such as the capability to query using concept hierarchies. An example orchestration system demonstrates the use of the geospatial service catalog for query evaluation in an automatic orchestration system (both fully and semi-automatic orchestration). Computational complexity analysis and experimental performance analysis identify potential performance problems in the geospatial service catalog. Solutions to these performance issues are presented in the form of partitioning service instance realization, low cost pre-filtering of service instances, and pre-processing realization. The resulting model and catalog provide an architecture to support automatic orchestration capable of complementing the multiple service composition algorithms that currently exist. Importantly, the geospatial service model and catalog go beyond simply supporting orchestration systems. By providing a general solution to the modeling and discovery of geospatial Web services they are useful in any geospastial Web service enterprise.

Finally, we perform a series of experiments employing several replication schemes and compare them with a non-redundant single service. Through the experiments, we evaluate both the reliability of the Web service paradigm and the correctness of the Web service composition algorithm. / In the paradigm, N-version programming technique is applied to increase the diversity of the system. As different versions of Web services or even different versions of their components are abundantly available in the Internet, the combination of different versions of the Web service or their components is thus becoming critical for enabling different versions in a server application using the N-version approach. We propose a dynamic Web service composition algorithm and evaluate with Petri-Net for verification purposes. / Moreover, we model the Web services with Markov chains and Petri-Nets to demonstrate the performance and reliability of the constructed Web services. Also, we develop the mathematical models to analyze the reliability of the Web services. / One of the latest achievements of the Internet usage is the availability of Web services technology and its dependability is becoming one of the most critical goals in Web related research. In this thesis, we propose a design paradigm for reliable Web services and a Web service composition algorithm. We describe the methods of dependability enhancement by redundancy in space and redundancy in time, using Round-robin scheduling technique, N-version programming and recovery block. The Web services are coordinated by a replication manager. It provides a Round-robin algorithm for scheduling the workload of the Web services and keeps updating the availability of each Web service. The replication algorithm and the detailed system configuration are described. / Chan, Pik Wah. / "March 2008." / Adviser: Micheal R. Lyn. / Source: Dissertation Abstracts International, Volume: 70-03, Section: A, page: 0722. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 114-124). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.